--- CRM/Utils/Rule.php	2009-09-21 05:11:35.000000000 +0000
+++ ../../../default/files/civicrm/custom/php/CRM/Utils/Rule.php	2010-03-16 20:00:51.000000000 +0000
@@ -428,7 +428,8 @@
             return true;
         }
 
-        return preg_match( '/(^\d+\.\d?\d?$)|(^\.\d\d?$)/', $value ) ? true : false;
+        // negative money fix for imba
+        return preg_match( '/(^-?\d+\.\d?\d?$)|(^-?\.\d\d?$)/', $value ) ? true : false;
     }
 
     static function string($value, $maxLength = 0)